Oil burner



March 3, 1942.

D. J. HQJVARD OIL BURNER Filed April 19, 1959 H w y u T w 122 H m y n vII M I I ia. UIMVI "J .u $0 u 1 WW a m m a \o w w o a 2 w a\ 0 a w H o iM 0 0? u o u W0 W H 2 dl I l 2 n. m m I 7 4 5 j Patented Mar. 3, 1942OIL BURNER David J. Howard, Chicago, 111., assignor to Quaker IManufacturing Company, Chicago, 111., a corporation of IllinoisApplication April 19, 1939, Serial No. 268,706

14 Claims.

This invention relates to certain new and useful improvements in aburner for liquid fuel,

' such as oil, and more particularly to improvements in the pilot-ringusedwithin a burner of the open pot type. I

One well known type of oil burner comprises a pot member having an opentop and a closed bottom, and provided witha plurality of spaced openingsin the upright cylindrical wall through which combustion air isadmitted. Oil is admitted into the lower portion of the pot and whenvaporized and mixed with air burns through the large central opening inan annular member which partially closes the top of the pot. An annularpartition or pilot-ring is mounted at an intermediate height within thepot, and. when the supply of oil and air is reduced a smaller pilotflame will burn adjacent this ring and through the large central openingtherein, the pilot-ring functioning much the same as the annular topmember functions when .the supply of oil and air is increased to sustainthe maximum fire. Prior to the present invention this pilot-ring has hada sufficiently large outside diameter to fit snugly within the potagainst the cylindrical side wall thereof so that all flow of gases oroil between the portions of the pot above and below thepilot-ring mustpass through the large central opening in the ring. According to thepresent invention the outer diameter of the pilot-ring is decreasedsufllciently to leave a passage of substantial width between the ring Iand the side wall of the pot, and means'are provided for centering thering so that the annular the ring and pot will 3 space or passagebetween be of substantially uniform width throughout the circumference.This annular passage permits a flow of gases directly adjacent the sidewall of the pot and materially improvesthe functioning of the burner aswill be set forth in detail hereinafter.

The principal object of this invention is to provide an improved burnerfor liquid fuel as briefly described hereinabove and disclosed in de-'tall in the specifications which follow.

Another object is to provide an improved form of pilot-ring foroil-burners of-the pot type.

Another object is to provide improved means for centering a pilot-ringwithin the burner pot.

Another object is to provide an improved sectional pilot-ring.-

Other objects and advantages of this inven-- tion will be more apparentfrom the following detailed description of one approved form of tilapparatus constructed and operating according to the principles of thisinvention.

, In the accompanying drawing:

Fig. l is a central vertical section through the burner assembly.

Fig. 2 is a partial horizontal section, taken substantially on the line2-4 of Fig. 1.

Fig. 3 is a detail section taken substantially on the line 3-3 of Fig.2.

The main inner housing or pot I is open at the top and comprises aclosed bottom portion 2 which is preferably slightly dished or concave,and an upright cylindrical side wall 3. The oil or other liquid fuel issupplied through a pipe I connected into the inlet nipple 5 near thebottom 2 of the pot. flows in through pipe is suitably controlled tofeed oil at a predetermined rate onto the upper surface-of the bottom 2of the pot, thus determining the size of the flame.

The required air for mixing and combustion purposes is supplied througha plurality-of holes formed in the side wall 3 of the pot I. In theexample here shown these holes are arranged in several circumferentialrows indicated at 6,1,

I0 which is located adjacent the upper open end of the pot.

The bottom and sides of the pot I are completely enclosed in an outerhousing II which is partially closed at the top by an annular wall I2.

An outturned flange I3 at the top of side wall 3 of the pot rests on theinner flange ll of top wall I2 thus suspending the pot I within thehousing I I. Air under controlled pressure may be forced into housing II through the air-tube I5 leading from a suitable blower or fan. Inorder to most advantageously distribute the air supply in housing II tothe several inlet openings 6 to ID inclusive in the burner pot I anintermediate shell'l6 is preferably positioned between the pot I and theouter housing II. This shell I6 is provided with a large central openingI! in its bottom so that a considerable portion of the air flow willpass through this opening I! and across the bottom 2 of the pot beforereaching the inlet openings 6 to 9. This flow of air serves to preventover-heating and burning I 55 out of the pot bottom 2, and also servesto pre- The rate at which the fuel heat the air before this air reachesthe combustion zone. Preferably a circumferential series of openings I8is provided in the upper side wall portion of shell I6 through which airmay pass directly to the upper row of pot openings l0. As far as thepresent invention is concerned it is not essential that the air besupplied to the several rows of inlet openings to ill in the preferredmanner hereinabove described by way of example. The burner may operateby natural draft, the air being drawn into the pot through the severalopenings by suction from above the upper open end of the pot.

The top of the pot l is partially closed by the fire-ring IS in the formof an annular metal plate resting on the top wall I2 and providedintermediate its inner and outer edgeswith a downwardly extendingcircular flange engaging within the side wall 3 of the pot so as toproperly center the fire-ring. For convenience in manufacturing andassembling this ring l9 may be made in two similar semi-circularsections which overlap at the meeting ends as indicated at 2|.

When this burner is operating normally at high fire, that is so as toprovide the maximum heat, oil introduced onto-the bottom 2 of the potwill be vaporized by heat from above and mixed with primary air flowingin through the lower rowsv of openings 6, 'l, '8 and 9 and then burnedby combining with the secondary or combustion air flowing in through theupper row of openings in. The flames will extend from adjacent theseopenings Hl through the large central opening or burner throat 22 in thefire-ring l9 and thence upwardly into the combustion space above theburner. At this time practically all of the flame is above the pot lwhich serves as a vaporizing chamber and as a mixingchamber for the fueland air before combustion actually takes place.

It has been found useful, in order to facilitate starting the fire andcontrolling the fire at lower stages to use a pilot-ring or auxiliaryfire-ring within the pot as indicated generally at 23. This ring isusually in the form of an annular metal partition fitting closely withinthe pot at its outer edge and provided with a large central opening 24comparablewith the similar opening 22 in the upper fire-ring l9. Thispilot-ring 23 is supported on a circumferential series of studs or pegs25 projecting inwardly from the side wall 3 of the pot, thussubstantially dividing the pot chamber into upper and lowercompartments. The ring 23 may be used at selected positions within thepot by supporting the ring on alternative series of pegs 25 or 25".Usually a suitable positioning for the ring will be at a heightsubstantially midway the top and bottom of the pot as indicated in thedrawing. I

The fire is started by igniting the shallow pool of oil introducedthrough pipe 4 onto. the pot bottom 2. The oil will burn here for ashort time until sufficient heat is created to vaporize a portion of theoil after which these oil gases will carry up the flame so that it willburn from the air inlets such as 6 and 1 below the pilotring 23 andproject upwardly through the central opening 24 in this ring. At thistime the through openings 6 and I, and then burned under and at thecentral opening in the pilotring. At this time the pilot-ring functionsmuch the same as the upper fire-ring l9 does when the high fire isburning. This fire burning in and directly below the ring 23 is the lowor pilot fire which is maintained continuously after the desiredtemperature has been reached in the space being heated. When more heatis required, the supply of oil and air is increased and the flame thenleaves the pilot-ring 23 and burns (for an intermediate fire) in thespace between the rings I9 and 23 and extending upwardly through 'theopening in fire-ring I9, and eventually (for a high fire as alreadydescribed) burning almost entirely outside and above the pot.

The operation of this type of burner as thus briefly described has beengreatly improved by the new type of pilot-ring which forms the particular subject matter of this invention and which the outer peripheryof the pilot-ring and the wall of the burner chamber. Thispassagepermits a free flow of gases along the inner wall of theburner-pot between the portions of the mixing and combustion chamberabove and below the pilot-ring. In order to insure the proper centeringof the pilot-ring within the pot, the ring is provided With acircumferential series of outwardly projecting lugs or fingers 21 whichengage the inner wall of the pot so that the annular passage 26 will beof uniform width at all sides of the ring. These lugs 21. are small andonly sufficient in number to insure the centerin of the ring so that thepassage 26 will be practically continuous around the entirecircumference of the ring.

This new form of spaced pilot-ring improves the operation of ,the burnerin many respects. When the former type of pilot-ring fitting tightlyagainst the pot at its outer edge is used, there is a tendency for thefire to snuff out during the initial stages before the burner is veryhot and before the pilot-flame has been well established at and directlybeneath the central openformed by vaporization of the oil and thesegases.

in the absence of suflicient combustion air, blanket the flame so thatthe fire goes out. Since the air inlet holes beneath the pilot-ring arerather widely spaced apart a certain amount of the vaporized oil willnot be mixed with the air from these holes. Some of this unburned gaswill be held down by the pilot-ring and will tend to blanket and snuffout the flame, while some will come up through the center opening 24 inthe ring. .These gases rising through the center opening 24 will havepartial combustion with air entering from the holes above the pilot-ringbut this flame burns almost entirely at the center of the burner chamberand because combustion is not complete the flame is dirty and aconsiderable deposit of soot will be left on the side wall of the burnerbetween the pilot-ring 23 and upper fire-ring l9. Probably this ispartly on account of an undue cooling of the side-wall, and the airintroduced above, as from holes 8, and flowing over the top of thepilot-ring has a coolin effect on the ring itself and thereby slows upthe vaporization of the oil in the lower portion of the burner-chamber.

With the new improved pilot-ring herein disclosed portions of theunburned gases float up in the spaces between the air Jets from theopenings beneath the ring and through the outer annular passage 28between the ring and side wall I and come in direct contact with the aircoming in through the staggered openings above the ring.

This mixture of air and gases will ignite and burn above the pilot-ringand at varying distances from wall 3 since the velocity of the incomingair streams will vary from time to time due to in constant draft. Theflames seem to dance across the upper surface of the pilot-ring, attimes burning almost adjacent the side wall openings and at other timesnearer the center of the ring.

As a result there is more complete combustion in the burner and a muchcleaner flame, especially between the pilot-ring and upper fire-ringwhen operating at intermediate flre. A'stronger and steadier pilot-flameis maintained and there is no tendency during the starting period forthe rich vaporized gases to buildup unduly within the lower portion ofthe chamber and snufl out the flame. There is less tendency for soot tobe deposited on the inner walls of the burner chamber, and the flamesburning adjacent the sidewall above the pilot-ring would tend to burnaway. any carbon deposits which might form and thus keep the potcomparatively clean. Also the flames burning directly above thepilot-ring keep the ring at a higher temperature, the heat projecteddownwardly from this ring helping to vaporize the oil.

Even after "high fire is. established and the actual combustion occursmostly outside the bumer chamber (that is the flames originate directlybelow the upper ring I! and project upwardly from and through thecentral opening 22 in this ring) the vaporized oil and primary airwithin the burner chamber-is more efliciently milled because of theadditional flow of gases through the annular space 28. between thepilot-ring and side-wall 3 of the pot.

v In order to facilitate installation and removal of the pilot-ring 23,this ring is preferably made in two or more similar arcuate sections.-In the preferred form here shown, the ring is divided into two similarhalf sections. The end portion 2| of one section overlies and rests uponthe depressed portion at the end of the other secprovided with aplurality of air inlet openings. distributed in spaced .apart relationthroughout the circumferential area of the side wallbetween the p andbottom thereof, means for introducing air through these openings, meansfor introducing liquid fuel into the lower portion ofthe pot, afire-ring forming an annular top member for partially closing the top ofthe pot, a pilot tire-ring forming an annular partition member I havinga large central aperture, and means for supporting said partition memberwithin the pot at an intermediate height, said partition having an outerdiameter substantially'less than the inner diameter of the pot. so that.an annular gas passage of substantial width will remain between theouter edge of the partition and the side wall of the pot, and means forcentering he p rtition so that the passage will be of uniform widththroughout the circumference of the pot.

2. In a burner for liquid fuel, a pot member having an open top, asubstantially. cylindricalside wall and a closed bottom, the side wallbeing provided with a plurality of air inlet openings distributed inspaced apart relation throughout the circumferential area of the sidewall between the top and bottom thereof, means for introducing airthrough these openings, means for introtion, and a tongue It extendingflrst'upwardly and then outwardly from the depressed portion 28 isinserted upwardly through a passage, II and then received in a pocket 32formed above the depressed portion 33 of the first mentioned section.

The two ring sections are identical, each having a tongue III at one endand a tongue-receiving pocket I2 at the other end. The sections areJoined in an obviousv manner by first tipping the meeting ends of thesections upwardly so that each tongue II can be inserted through apassage ll, after which the sections are swung down to normal positionand the parts are engaged as side wall and a closed bottom, the sidewall being ad] acent the pot wall.

ner diameter of the passage of substantial width will remain between iducing liquid fuel into the lower portion of the pot, a fire-ringforming an annular top member for partially closingthe tend the pot, apilot fire-ring forming an annular partition member having a largecentral aperture,-and means for supporting said partition member withinthe pot at "an intermediate height, said-partition being formed toprovide a substantially continuous annular gas passage of uniform widthbetween the outer portion of the partition and the adjacent wall of the.pot.

,3. In abu'rner for liquid fuel, a pot member having anopen top, a.substantially. cylindrical side wall and a closed bottom, the side wallbeing provided with a plurality of air inlet openings distributed inspaced apart relation throughout the circumferential area of thesidewall between v the top and bottom thereof, means for introducing airthrough these openings, means for introducing liquid fuel into the lowerportion of the pot, a fire-ring forming an annular top member'forpartially closing the top of the. pot, a pilot fire-ring forming anannular partition mem-.

her having a large central aperture, and means for supporting saidpartition member within the pot at an intermediate height, saidpartitionbeing apertured adjacent its outer edge to. provideasubstantially continuous annular gas passage 4.'In a .bumer for liquidfuel, a .pot member having an open top, a substantially cylindrical sidewall and a closed bottom, the side wall being provided with a pluralityof air' inlet openings distributed in spaced apart relation throughoutthe circumferential area of the side wall between the top and bottomthereof, means for introduc-- ing air through these openings, means forintroducing liquid fuel into the lower portion of the.

pot, a fire-ring forming an annular top member for partially closing thetop of he pot, a pilot fire-ring forming an annular partition memberhaving a large central aperture, and means for supporting said partitionmember within the pot at an intermediate height, said partition havingan'outer diameter substantially less than the in pot so that an annulargas the outer edge of the partition andthe side wall of the pot, andmeans for centering the partition so that the passage will be of uniformwidth throughout the circumference of the pot comprising a plurality oflugs projecting from the partition and engaging the side wall of thepot.

5; In a bu'rneriorliquid fuel, a pot. member having an open top, asubstantially cylindrical side wall and a closed bottom, the sidewallbeing provided with a plurality of air inlet openings distributed inspaced apart relation throughout the circumferential area of the sidewallliet'ween the top and bottom thereof, means for introduc ing airthrough these openings, means "for introducing liquid fuel into thelower portion of the pot, a fire-ring forming an annular top member pctwall.

8. An auxiliary fire-ring for use in the pilot throughout its outercircumferential portion to permit a flow ofgases between the partitionand name of a liquid fuel bumer'of the pot type, said ring comprising anannular plate designed to be supported in 'a position extendingtransversely within an-intermediate portion of the pot with itslarge'central aperture leftopen for the free passage therethrough ofgases from the lowerortion ofthe pot to the space above the ring;

said ring also being apertured uniformly throughout its outercircumferential'portion to permit a more restricted flow of gasesbetween the ring and pot wall. 4 v

-9. An auxiliary fire-ring for use in the pilot flame of a liquid fuelburner of the pot type, said.

ring comprising an annular plate designed to be supported in a positionextending transversely within an intermediate portion of thepot with itslarge central aperture left open for the free passage'therethrough ofgases from the lower portion of the pot to the spaceabove the ring,

so that the passage will be of uniform width Y throughout thecircumference of the pot comprising aplurality of lugs of equal lengthprojecting radially from the partition at equally spaced intervals andengaging the side wall of the pot.

6. In a burner for liquid fuel, apot member having an open top, asubstantially cylindrical side wall and a closed bottom, the side wallbeing provided with a'plurality of air inlet openings distributed inspaced apart relation throughout the circumferential area of the sidewall between the top and bottom thereof, means for introduc ing airthrough these openings, means for introducing liquid fuel into the lowerportion of the pot, a fire-ring forming an annular top member forpartially closing the top of the pot, a pilot fire-ring forminganannular partition nfem-ber having-a large central aperture, and meansfor supporting said partition memberwithin the pot at an. intermediateheight, said partition having an outer diameter substantially less thanthe inner diameter of the pot so that an annular gas Passage ofsubstantial width will remain between the outer edge of the partitionand the side wall of the pot, and means for centering the partition sothat the passage will ,be of uniform width throughout thecircumferenceof the pot comprising a plurality of lugs of equal length projectingradially from the partition at equally spaced intervals and engagingtheside wall of the pot, said partition being formed of detachablyconnected arcuate sections to facilitate installation in and removalfrom the pot.

7. In a burner for liquid fuel, a pot member having an open-top, asubstantially cylindrical side wall and a closed bottom, the side wallbeing ,provided with a plurality of air inlet openings 'dstri'outed inspacedapart relation throughout the circumferential area of the sidewall between the top and bottom thereof, meansfor introducing airthrough these openings, means for intro- V ducing liquid fuel into thelower portion of the pot, a fire-ring forming an annular top member forpartially closing the top of the pot, a pilot' fire-ring forming. anannular partition member fitting transversely within the pot and havinga large central aperture; and means for supporting said partition withinthe pot at an intermediate height, said partition being apertureduniformly said ring having an outer diameter substantially less than theinner' diameter of the pot; and means for centering the ring within thepot so as to provide an additional gas passage'of uniform widthbetweenthe ring andpot wall. t

10. An auxiliary fire-ring for use in the Pilot flame" of a liquid fuelburner of the pot type, said ring' comprising an annular plate designedto be supported in a position extending transversely within theintermediate portion of the pot with its large central aperture leftopen for the free passage 'therethrough of gases from the lower portionof the pot to the space above the ring and having a series of centeringlugs of equal length projecting outwardly from the outer edge of theplate at spaced apart intervals and adapted to engage the inner surfaceof the pot wall and thus provide a circumferential series of arcuate gaspass-ages of similar width, between the lugs,

. and between the outer edge of the ring'and the inner surface of thepot wall.

.gases from the lower portion of the pot to the space above the ring,said ring having an outer diameter substantially less than the innerdiameter of the pot, and means for centering the ring within the pot soas to provide an additional gal passage of uniform width between thering and pot wall.

12. An auxiliary fire-ring for use in the pilot flame of a liquid fuelburner of the pot type, said ring designed to be supported in a positionextending transversely within the intermediate portion of the pot withits large central aperture left Y open for the free passage therethroughof gases from the lower portion of the pot to the space above the ringand having a series of centering lugs of equal length projectingoutwardly from the'outer edge of the plate at spaced apart intervals andadapted to engage the inner surface of the pot wall andthus provide acircumferentlal series of arcuate gas passages of similar width, betweenthe lugs, and between the outer edge of the ring and the inner-surfaceof the pot wall.

13. Ina burner ofthe character described, a

casing defining an oil vaporizing and air mixing chamber havingperforated side walls and a burner throat in a top wall, and meanssubstantially dividing said chamber into upper and lower compartmentsand afiording vapor passage to said throat at the center of said chamberand along the edge of said chamber along the side walls.

14. In a liquid hydrocarbon burner, a pot having a plurality of airinlets in its wall located at various levels therein, said burner havinga bottom portion, means for delivering a controlled volume of fuel tosaid bottom portion, a pilot baiiie located intermediate the top and thebottom of the pot, and means for supporting it, the outer edge of saidbaiile being spaced inwardly from the inner face of the pot, said bafliehaving a central opening.

DAVID J. HOWARD.

